add basic component test for pagination

__tests__/components/Pagination.test.jsx

@@ -0,0 +1,72 @@
+import React from 'react';
+import { mount } from 'enzyme';
+import Pagination from '../../src/components/Pagination';
+
+describe('<Pagination />', () => {
+  const noop = () => {};
+
+  let pagination;
+
+  afterEach(() => {
+    if (toolbar) {
+      pagination.unmount();
+      pagination = null;
+    }
+  });
+
+  test('it triggers the expected callbacks on next and last', () => {
+    const next = 'button[aria-label="next"]';
+    const last = 'button[aria-label="last"]';
+
+    const onSetPage = jest.fn();
+
+    pagination = mount(
+      <Pagination
+        count={21}
+        page={1}
+        pageCount={5}
+        page_size={5}
+        pageSizeOptions={[5, 10, 25, 50]}
+        onSetPage={onSetPage}
+      />
+    );
+
+    pagination.find(next).simulate('click');
+
+    expect(onSetPage).toHaveBeenCalledTimes(1);
+    expect(onSetPage).toBeCalledWith(2, 5);
+
+    pagination.find(last).simulate('click');
+
+    expect(onSetPage).toHaveBeenCalledTimes(2);
+    expect(onSetPage).toBeCalledWith(5, 5);
+  });
+
+  test('it triggers the expected callback on previous and first', () => {
+    const previous = 'button[aria-label="previous"]';
+    const first = 'button[aria-label="first"]';
+
+    const onSetPage = jest.fn();
+
+    pagination = mount(
+      <Pagination
+        count={21}
+        page={5}
+        pageCount={5}
+        page_size={5}
+        pageSizeOptions={[5, 10, 25, 50]}
+        onSetPage={onSetPage}
+      />
+    );
+
+    pagination.find(previous).simulate('click');
+
+    expect(onSetPage).toHaveBeenCalledTimes(1);
+    expect(onSetPage).toBeCalledWith(4, 5);
+
+    pagination.find(first).simulate('click');
+
+    expect(onSetPage).toHaveBeenCalledTimes(2);
+    expect(onSetPage).toBeCalledWith(1, 5);
+  });
+});